fix: apply persisted GPS enabled setting on boot for companion radio

The companion_radio example was not restoring the GPS enabled/disabled
preference from flash after reboot. The preference was being saved
correctly when toggled via the mobile app, but on boot,
sensors.begin() -> initBasicGPS() unconditionally sets gps_active=false
and nothing subsequently restored the persisted state.

Added applyGpsPrefs() (matching the pattern in simple_repeater,
simple_sensor, and simple_room_server) and call it from main.cpp
after sensors.begin() to ensure the GPS hardware is initialized
before the saved preference is applied.

examples/companion_radio/MyMesh.h

@@ -165,6 +165,12 @@ protected:
 public:
   void savePrefs() { _store->savePrefs(_prefs, sensors.node_lat, sensors.node_lon); }
 
+#if ENV_INCLUDE_GPS == 1
+  void applyGpsPrefs() {
+    sensors.setSettingValue("gps", _prefs.gps_enabled ? "1" : "0");
+  }
+#endif
+
 private:
   void writeOKFrame();
   void writeErrFrame(uint8_t err_code);

examples/companion_radio/main.cpp

@@ -213,6 +213,10 @@ void setup() {
 
   sensors.begin();
 
+#if ENV_INCLUDE_GPS == 1
+  the_mesh.applyGpsPrefs();
+#endif
+
 #ifdef DISPLAY_CLASS
   ui_task.begin(disp, &sensors, the_mesh.getNodePrefs());  // still want to pass this in as dependency, as prefs might be moved
 #endif